Before leaving for your first (or next) Thailand trip, learn some useful expressions. The locals will appreciate if you make an effort to speak in their language.
Good morning = Sawadd ton chow
Good day/ Hello = Sawadii
Good night = Sawadd ton yin
Good bye = Lagawn
See you = Påbb gann mai
My name is = Chue
How are you? = Sabai dii mai?
Thank you = Kåb kunn
Do you speak English? = Kunn pood pasaa Angritt die mai?
It was nice to meet you. = Yin dii tii daai roo djack
Good luck! = Chååk dii!
I am fine = Sabai dii
How much does this cost? = Tao rai
Can you lower the price? = Lod dai mai
I like this = Chawp aun nee
I like that = Chawp aun nun
Do you have any other colour? = Mee see aeun bang mai
Shop = Ran kaa
Toilet = Hong nam
Clothes = Sier par
Shoes = Rong tao
Watch = Nar ri ka
How much? = Tao Rai?
Restaurant = Ran ar harn
Where is the clothing shop? = Ran kaa Sier par u tee nai
Where is the toilet? = Hong nam u tee nai
Where is the restaurant? = Ran ar harn u tee nai
Update: A big thanks to Matt who helped me correct some of the phrases. I started learning Thai a while ago and am by no means an expert. If you find another error, do let me know.